Two-decade trends and factors associated with overweight and obesity among young adults in Nepal

Overweight and obesity are global epidemics in the adult population, and also affect young people. This study estimated the long-term trend (1996-2019) of overweight and obesity among young adults aged 18 to 29 years in Nepal by sex based on the World Health Organization (WHO) and Asian cut-offs for body mass index (BMI). We also investigated the demographic factors associated with overweight and obesity in the latest survey. This study utilized data from nationwide studies, Demographic and Health Surveys (DHSs) and WHO STEPwise approach to surveillance (STEPS) surveys. The trends in overweight and obesity were studied using trend analysis and joinpoint regression. Average annual percent changes (AAPCs) and their 95% confidence intervals (CIs) were calculated for the trends. Multivariable logistic regression was used to study the factors associated with overweight and obesity. The study findings showed significant upward trends in both overweight and obesity for women with AAPCs of 10.5 (95% CI 6.4-14.7) and 15.8 (95% CI 10.9-20.8) respectively. In the 25-29 age-group, the prevalence of overweight/obesity increased among women from 2.2% to 24.7% between 1996 and 2019, and among men from 8.8% to 25.4% between 2007 and 2019. Increased odds of overweight (AOR 9.15, 95% CI 6.64- 12.60), and obesity (AOR 42.09, 95% CI 10.12-175.04) were found in 2019 compared to 1996. Older age and female sex, being married and urban residence were significantly associated with overweight and obesity. In conclusion, this study showed rapid upward trends in overweight and obesity among young adults in Nepal with an accelerated trend among women; the predictors for overweight were older age, female sex and married status, and those for obesity were older age, female sex, and urban residence.